| abstract |
ABSTRACT: A process for producing threo-3 amino-2-hydroxybutanoyl-aminbacetic acids comprises the steps of allowing to react a starting compound represented by the general formula: (I), wherein R1 represents a naphthyl or a group of the formula: in which R6 and R7 represent individually hydrogen, halogen, amino or a protected amino, hydroxy or a protected hydroxy, a lower alkoxy, a lower alkyl or phenyl and R2 represents a protected amino, with a starting compound represented by the general formula: (II), wherein R3 represents hydrogen or an ester residue, to obtain threo-3-protected amino-2-hydroxy-4-oxobutanoic acid or its ester represented by the general formula: (III), wherein R1, R2 and R3 have the same meanings as above, and then reducing the same into threo-3-protected amino-2-hydroxybutanoic acid or its ester represented by the general formula: (IV), wherein R1, R2 and R3 have the same meanings as above, and further converting the above compound into threo -3-amino-2-hydroxybutanoic acid represented by the general formula: (V), wherein R? represents amino or a protected amino, thereafter condensing the same, in a conventional manner for forming a peptide bond, with a compound represented by the general formula: (VI), wherein R4 represents an alkyl having 3 - 4 carbon atom or 3-guanidinopropyl, while previously protecting as required those groups not relevant to the reaction, and removing the protecting groups for the functional groups to produce threo-3-amino-2-hydroxybutanoylaminoacetic acids represented by the general formula: (VII), wherein R1 and R4 have the same meanings as above. This inven-tion also provides the compounds represented by the general formula (III) as novel intermediates for the above aimed compounds and a process for producing the intermediates. |